1968 Evinrude Big Twin, Big Twin Electric, Lark 40 HP Outboards Service Manual, Page 52Get this manual
Figure 5-24Checking Ring Gap in Cylinder Before installing new piston rings, check gap between ends of ring placing ring in its respective cylinder then pushing the ring down in the slightly with the bottom of the piston to square it Discard and replace with new ring if gap is excessiveSee Figure 5-24Check each ring in its respective ring groove for evidence of tightness binding rolling the ring around the piston ring grooveSee Figure 5-25 Check for groove side clearance with feeler gageSee Figure 5-26Correct gap and side clearances given in Section 2 Figure 5-26Checking Groove Side Clearance and free from dirt and gritPerfectly good cylinder walls, pistons and rings ruined in few minutes of operation unless forms of grit removed before assemblyWork in clean surroundings and with reasonably clean handsCoat ing surfaces, cylinder walls, etc with clean before assemblyNOTE Always use new gaskets and seals throughout when reassembling the power headPISTONS, WRIST PINS, AND RODS
REASSEMBLY OF POWER HEAD